The primary aim is to ascertain the efficacy of Vitamin A supplementation administered during the first month of age to ELBW infants (<1,001 grams) in reducing the risk of death or chronic lung disease. Eligible infants will be assigned randomly to a treatment (Vitamin A) or no treatment group. Infants in the treatment group will be given 5000 IU of Vitamin A intramuscularly on Monday Wednesdays and Fridays. Treatment will continue for 4 weeks after entry. Infants in the no treatment group will not receive placebo injections.